The standard time library from Haskell 98. This library is
deprecated, please look at Data.Time in the time package
instead.

System.Time provides functionality for clock times, including
timezone information (i.e, the functionality of "time.h",
adapted to the Haskell environment). It follows RFC 1129 in its
use of Coordinated Universal Time (UTC).

converts an internal clock time to a local time, modified by the
timezone and daylight savings time settings in force at the time
of conversion. Because of this dependence on the local environment,
toCalendarTime is in the IO monad.